Hand trucks provide a convenient two-wheeled apparatus which is capable of engaging, supporting, and transporting an object. Typically, a support plate extends at a right angle forward from the body of the hand truck in close proximity to the ground. The object is lifted by positioning the object on the support plate and rotating the hand truck backward about the wheel axis, causing the object to rest on both the support plate and the body of the hand truck. The object may then be moved by rolling the hand truck on its wheels. Thus, hand trucks provide a simple mechanism for moving large, or otherwise cumbersome, objects.
As an example, welding equipment is both large and cumbersome to transport. Oxygen and fuel storage cylinders are difficult to handle by themselves. Hand trucks have been designed to store and transport these gas cylinders to facilitate the use of the welding equipment. Typically, the cylinders are placed on the forwardly extending support plate and secured against the body of the hand truck by straps, chains, or similar retainers. The individual cylinders are thus grouped as a unit and adapted to be readily transported about an area where the welding equipment is to be utilized.
The forwardly extending support plate creates problems associated with storing and transporting the hand truck. Typically, the support plates are welded or otherwise rigidly secured to the body of the hand truck. Side brace members, extending from the body of the truck to the sides of the support plate, may additionally be utilized to provide support to the support plate. When these rigid hand trucks, with or without side brace members, are stored in a box for shipment, a significant amount of space therein is wasted to accommodate the outwardly extending support plate. Correspondingly, valuable space on a cargo carrier is also wasted.
Support plates which are bolted to the body of the hand truck have been used to address the problems associated with fixed support plates, but have created additional problems. When this type of hand truck is shipped with the support plate unattached to the hand truck, a merchant or purchaser must thereafter bolt or otherwise secure the support plate to the body of the hand truck. The required assembly of the parts is tedious, the hand truck may be improperly assembled, and further the loose parts may be lost in shipping.
Pivotable support plates have also been used to address the problems associated with fixed support plates, but have created additional problems, as well. Specifically, the support plate may break off under the significant downward forces associated with transporting heavy objects, if not supported adequately.
The prior art has addressed the problems associated with pivotable support plates by either providing substantial connector and stop plate arrangements to withstand the load forces or providing folding side braces which are connected at opposite ends to the support plate and the boy do the hand truck and adapted to fold about a central pivot point when the support plate is pivoted. Both of these prior art structures are relatively costly to manufacture and require a plurality of parts which must be assembled and maintained.